Endophenotype: Also known as intermediate phenotype, this genetic epidemiology term is used to separate behavioral symptoms into more stable phenotypes, which may reflect more elementary processes with a clear genetic connection. A quantitative biological trait that is reliable in reflecting the function of a discrete biological system and is reasonably heritable may be more closely related to the root cause of the disease than the broad clinical phenotype or complex psychiatric phenomena, typically defined by exceeding a symptom threshold.
